BSS Audio FDS366T OMNIDRIVE User Manual page 96

Serial Communications
RS232 to RS485 Converters
RS232
Termination resistor fitted
Example multidrop network of FDS-
366T with other RS232 only BSS
At the time of writing the FDS-366T Omnidrive is the only BSS unit to have
built in RS485 support however, a multidrop system can be used with RS232
equipped devices, such as the FDS-355, Minidrive models or a PC, using
RS232 to RS485 converters.
Most RS232/RS485 converters can be run in either 2 or 4 wire mode. For use
with an RS485 multidrop system across FDS-366T's they only need to be set
up in 2 wire mode. 4 wire mode should only need to be used to extend an
RS232 cable over 50feet.
To connect a multidrop network of FDS-366Ts to a PC, for use with software
such as BSS Audio's Soundbench for example, it is very likely that an RS485
interface will need to be fitted to the computer, either as an internal card or as
an external converter connected to the PC's RS232 serial port.
Converter Example multidrop network of FDS-366Ts connected to a PC
RS485
MIDI channels should be set independantly. Termination and bias should be
applied, either by adjusting settings (if available) on the converter or as
discussed earlier, please consult your RS485 converter documentation.
FDS-366T Multidrop networks can also be arranged using units fitted with
RS232 only using converters as shown below. One converter per unit is
required set up in 2 wire (XMT- to XMT- and XMT+ to XMT+) mode. Biasing
should be fitted as discussed earlier and termination should be applied on just
the end nodes of the network. If different models are being used together care
must be taken with MIDI dumps to ensure that the data is only received by
compatible units. Use the MIDI channels to select only devices of the same
type.
5 4
RS485
units
Termination resistor fitted
RS485
RS485
Termination & biasing resistors fitted
RS232
Converters
RS232
RS232
- 96 -
FDS-366T
RS485
MIDI Mode: Multidrop
MIDI Channel: 1
MIDI Mode: Multidrop
MIDI Channel: 2
MIDI Mode: Multidrop
MIDI Channel: 3